1. Field of the Invention
The present invention relates to a method for fabricating an inter-metal dielectric layer. More particularly, the present invention relates to a method for fabricating an inter-metal dielectric layer, which reduces RC delay.
2. Description of the Related Art
Because the linewidth of devices is continuously shrinking, the parasitic capacitor effect between metal wires is increasingly serious and RC delay increases. The parasitic capacitor effect easily occurs because the dielectric constant of a dielectric material, which forms an inter-metal dielectric layer, is large. Dielectric material with a low dielectric constant is therefore chosen to overcome the above problem.
In conventional technology, however, the parasitic capacitor effect between metal wires is not always effectively decreased because the dielectric constant of the dielectric material is not low enough.